I understand that 12-w includes both employee and employer contributions. It is supposed to be tax-free, why adding these contributions affect my tax?

You need to finish accounting for it. In order for HSA contributions to remain without any tax consequences, Form 8889 must be completed on your tax return. On Form 8889, you describe your coverage in a High Deductible Health Plan, including who is covered and when. HSA contributions are not pretax or without tax consequences until Form 8889 says they are.

Please see this LINK for more information.

To get to Form 8889:

• Federal
• Deductions & Credits
• Medical
• HSA, MSA Contributions

thanks!

it was the trick